May 8, 2006 (芝加哥) — 根据美国后备军人事务部的一项新研究，使用Statin类药物和认知功能之间没有显著关联；然而，该研究发现Statin类药物因为社会人口因素而广被使用。
后备军人健康局老年研究教育暨
临床中心(VA-GRECC) 的主要负责人Richard M. Allman医师向Medscape表示，显然地，有服用Statin类药物和没有服用者之间是有所不同，而这些差异在于社会经济、行为和医疗等因素；为了校正这些变数，Allman医师向Medscape表示，他选择倾向分析作为统计工具。
VA-GRECC 对使用Statin类药物和认知功能的研究结果，发表在美国老年协会年度科学会议的壁报。
根据Allman医师所述，这种情况下测量效度的标准统计工具应该是多变项分析。
Allman医师向Medscape表示，我们做了多变项分析，结果却显示相同，他因而采用倾向分析，这是一种在比较实验组和对照组时可以降低差异的统计方法；倾向分析是当存有许多可能的危险因子时，用来使各组的差异减少的一种方法。
VA-GRECC 研究的原始样本是1000位阿拉巴马州居民，他们是联邦医疗保险的受惠者，也是阿拉巴马大学伯明罕校区(UAB) 老人研究对象，依照初步排除规范将样本缩小为792人，其中16% 有服用Statin类药物；整体的人口统计资料十分复杂，平均年纪为75岁、50%是非裔美国人、51%是女性、20%的教育程度是七年级(相当于我国国中一年级)以下。
VA-GRECC 研究采用电话访谈来搜集每个个案的资料，搜集的资料包括医疗状况和认知功能，测定方法是使用完整的简易心智量表(MMSE)测验访谈在开始时、第18个月时、第3年时各进行一次。
使用统计程式 SPSS 进行分析，包括属性对照、描述性统计和积差相关，使用复回归以量测使用Statin类药物在认知功能的效果。
然后，使用倾向分析以得到一个一比一的配对样本组，各是118 位使用Statin类和 118位未使用Statin类药物者。
研究发现，Statin类的使用因社会人口和其他因素而异；在3年追踪期满时，使用Statin类者有较高的MMSE 分数，但与认知功能并没有显著关联。
Allman医师向Medscape表示，当然藉由配对分析可以得到较小的样本量，说服力就显得不够，但是比较容易比较；他的结论是，在使用Statin者和未使用Statin者之间并无显著差异，而这个小样本在此所要表达的结果是，起始时的认知分数可以预测后续的MMSE认知测量；使用Statin者并无法预期后续分数可以改善，倾向显示无需使用statins。
Medscape访问George E. Taffet医师其反应，Taffet医师是老年医学专家、贝勒医学院医学系心脏科学部门老人科学组主任。
Taffet医师向Medscape表示，这个研究显然有些限制，我个人比较有兴趣了解的是，服用statins一段时间后、是否可以减缓认知状态衰退的情况，但是这是很吊诡的，这类药物并非灵丹妙药，只是有些人认为他们是。
No Relation Between Statin Use and Cognitive Function
By Richard Hyer
Medscape Medical News
May 8, 2006 (Chicago) — Statin use is not significantly associated with cognitive function, according to a new study by the US Department of Veterans Affairs. Statin use does, however, vary widely by sociodemographic factors, the study found.
"Clearly, the people on statins are different from the people that weren't taking statins," lead author Richard M. Allman, MD, from the Veterans Health Administration Geriatric Research Education and Clinical Center (VA-GRECC) in Birmingham, Alabama, told Medscape. The differences are socioeconomic, behavioral, and medical. To adjust for these variables, Dr. Allman told Medscape that he chose the statistical tool known as propensity analysis.
The results of the VA-GRECC study of statin use and cognitive function were described in a poster here at the annual scientific meeting of the American Geriatrics Society.
According to Dr. Allman, the standard statistical tool for measuring efficacy under these circumstances would be multivariate analysis.
"We did that, and the results ended up being the same," Dr. Allman told Medscape. This led him to use propensity analysis, a statistical device used to reduce bias in comparing treatment and control groups. Propensity analysis is designed to equate groups in the greatest possible number of risk factors.
The VA-GRECC study's original sample was a group of 1000 Alabama residents who are Medicare beneficiaries and were identified by the University of Alabama at Birmingham (UAB) Study on Aging. Preliminary exclusion criteria reduced the sample size to 792, of whom 16% were found to be taking statins. The demographics of the full sample were variable, including a mean age of 75 years, 50% were African-American, 51% were women, and 20% had an education less than seventh-grade level.
The VA-GRECC study used telephone interviews to collect data on each subject. The data collected included medical condition and cognitive function, as measured by the full Mini-Mental State Examination (MMSE) test. Interviews were conducted at baseline, 18 months, and 3 years.
The statistical program SPSS was used for analyses, including propensity matching, descriptives, and bivariate correlations. Multiple regression was employed to gauge the effect of statin use on cognitive function.
Propensity analysis was then used to create a 1:1 matched sample of 118 statin users and 118 non–statin users.
The study found statin use variable by sociodemographic and other factors. At the 3-year follow-up, statin use was associated with higher MMSE scores. It was not found to correlate significantly with cognitive function.
"In the matched pair analysis of course you get a smaller sample size, the power is not as good, but you feel like it's more comparable," Dr. Allman told Medscape. "You don't see a significant difference between the statin users vs the non–statin users. And basically this little model here is showing that baseline cognitive score predicts subsequent cognitive measures of the MMSE. Statin use was not predictive of subsequent scoring. Nor was the propensity towards using statins," he concluded.
For a reaction, Medscape turned to George E. Taffet, MD, a geriatrician and chief of the Section of Geriatrics in the Department of Medicine and Section of Cardiovascular Sciences at Baylor College of Medicine in Houston, Texas.
"The study definitely has some limitations," Dr. Taffet told Medscape. "I would be interested in seeing whether taking the statins over a period of time was associated with a decreased in cognitive status. But it's intriguing. They may not be the miracle drugs that some people think they are," he said.
AGS 2006 Annual Scientific Meeting: Abstract B31. Presented May 4, 2006.
Reviewed by Carol Peckham
作者：
Richard Hyer 2007-6-16